Concrete mixer and conveyer



Aug. 26, 1924. 1,506,089

K. R. SCHUSTER coucnsws MIXER AND convaysn Filed Dec. 6, 1919 ATTORNEY Patented Aug. 26, 1924.,

PATENT OFFICE.

KARL R. SCHUSTER, OF BROOKLYN, NEW YORK.

CONCRETE MIXER AND GONVEYER.

Application filed December 6, 1919. Serial No. 343,037.

To all whom it may concern:

Be it known that I, KARL R. Sonosrnn, residing at the city of New York, borough of Brookl 11, county of Kings, and State of New lork, have invented a certain new and useful Concrete Mixer and Conveyor, of which the following is a specification.

This invention is a process of and means for mixing and transporting mixtures such as concrete and analogous materials, wherein a gaseous fluid, such as air or gas, under pressure is utilized and controlled so as to effect an intimate admixture of the aggregates and to convey or transport the result ing mixture to the place of use.

The invention in so far as it pertains to the apparatus embodies a chamber provided,

' .in addition to a chargin opening, with an outlet opening for the a mixture and with an inlet opening for the air or gas, the area of the mixture outlet opening being preferably less than that of the charging opening, means for feeding air or gas under the required pressure to said mixing chamber whereby the aggregates are agitated to eifect the mixture, a gate for closing the charging opening during the period of agitation, a separate gate for closing the outlet during the mixing period, a rotatable agitator element operable within the chamber,.an offbearing conduit connected with the lower portion of the chamber, and means for feeding air or gas under pressure to the conduit in order to impart movement to the mixture present therein.

The invention includes means whereby the air or gas under pressure may be controlled so as to direct the same into the mixing chamber or into the conduit leading from said chamber, said means being embodied usually in the form of a three-way valve positioned in the pressure pipe.

The agitator element of my invention is positioned in the line of flow of the air or gas admitted to the mixing chamber, whereby rotary motion is imparted to the agitator element by the inflowing air or gas, as

- a result ofwhichthe agitator is driven by the 'same fluid, the pressure of which is utilized to mix the aggregates. Thefunction of this agitator is to preclude the lodgment of the coarse mineral aggregate within. the lower part of the chamber so as to'prevent the formation of an arch adjacent the mixture outlet or the pressure inlet,-and in furfduit at a point adjacent the outlet therefrom, the inflow of such air or gas at the specified point tending to create in the conduit a partial vacuum the: effect of which is to assist in the movement of the mixed mass within the conduit, whereby the mass is expelled and sucked through the conduit by air or gas pressure for the reason that air or gas is blown into the conduit either from the mixing chamber or at a point close to the chamber so as to exert pressure in rear of the mass while at the same time air or gas is admitted to the conduit adjacent the delivery as heretofore mentioned in order to create the suction in said conduit for the specified purpose, the effect of which is to transport or convey the mixture for long distances with a corresponding saving in energ time and labor.

Other functions and advantages of the invention will appear from the following description taken in connection with the drawings, wherein-- Fig. 1 1s a dlagrammatic sectional elevation of the apparatus embodying my invention.

' Fig. 2 is a similar view of another form be closed by a gate 6 of any suitable form,

whereby the outflow of the air or gas during the operation of mixing the aggregates is precluded, resulting in the accumulation 7 within the chamber of the air or gas employed to agitate such aggregates in effecting the mechanical admixture thereof. At the bottom part of tank A is an outlet 0 for the discharge of the mixture, and with this outlet communicates a conduit 13, the latter being shown in the form of a pipe having an elbow d attached in a suitable way to within the tank and acting directly upon the aggregates therein for imparting to such aggregates the motion required to stir them 11 and to effect the mechanical admixture thereof. In the apparatus shown in Fig. 1, said pipe D is provided with branches 6, f, the former being connected with conduit B at or adjacent its elbow d whereas the branch f is connected with the tank at or near the bottom part thereof. Said pipe D is provided, also, with a valve E, preferably a three-way cock the position of which controls the line of flow of the aseous medium supplied by the pipe D. Kdjusted to one position, the valve cuts off the flow of pressure either to the tank or to the conduit; adjusted to the position of Fig. 1, the valve opens the path for the flow of pressure from pipe D to tank A so that the air or gas flowsinto the tank for agitating the aggregates therein, but when moved to the third position, the valve cuts off the flow to the tank and directs it into conduit B at or adjacent the elbow in order that the fluid under pressure will be admitted to the mixed mass for transporting or conveying the same through said conduit, thus expelling the mixed mass by applying pressure rearwardly thereof. It wil be understood that the motive fluid is so controlled that its pressure is utilized first for agitating the aggregates in order to mix them, and, second, for expelling. the mixture from the tank and from the conduit. Any suitable means is, or may be, provided for the operation of valve E, as shown, a handle 6 is provided for turning said valve as required.

Within the tank is mounted an agitator element'F, the same being shown as comprising a series of radial arms f, a horizontal shaft f and paddles f all suitably at tached. The shaft is journaled in appropriate hearings in order that the agitator may rotate on a horizontal axis. The paddles f extend laterally from the arms, said paddles moving close to the air inlet and to the mixture outlet in order to sweep any material away from said openings and thus minimize the tendency of the materials to clog the openings. The agitator is rotated within the tank, it being preferred to so organize or relate the agitator to the fluid inlet that the inflowing air, steam or gas tributes to the agitation of the mass which agitation is initially established by the inflowing air, steam or gas; in fact, the agitation of the mass is due to the pressure of the air, steam or gas and to the mechanical action of the rotary stirrer; but the prima function of the rotative agitator is to brea up that tendency of the coarse mineral aggregate to arch across the lower part of the tank and thus to' come to a state of rest therein, precluding to a certain extent the desired thoroughness of the mixing operation. The conduit B is shown as tubular, and it is of any desired length, so as to extend from the mixing tank to the place where the concrete is to be utilized for building or other construction operations, the mixture being discharged through a delivery section B". To assist in the transportation or conveyance of the mixture in a long length of the conduit, it is preferred to utilize fluid pressure for creating a suction in the conduit, thus brlnging into active service the expelling force and the suction force of the motive fluid. To this end a pressure pipe G is em-- ployed, the same having a delivery nozzle 5/ extending into the delivery section B of the 1 conduit. This pressure pipe is supplied with motive fluid from a desired source; as shown it is coupled to the pressure pipe D and is provided with a valve or cock for admitting the fiuid as and when required.

The operation is as follows :lVith the gate 0 and cocks E 9' closed. the gate 7) is opened, and the materials to be mixed are supplied to the tank through the charging opening, after which gate 6 is closed, where- 115 as gate C remains in a closed condition. Valve E is now shifted to open the path from the pressure pipe D to the chamber, and thus air, steam or gas under pressure is admitted to the tank, the effect of which is 120 to rotate the agitator F and to agitate the aggregates by the conjoint action of the air, steam or gas upon such aggregates and bv the stirring or beating action of the element F. The motive fluid continues to flow into 125 the tank until the ,desired pressure is accumulated therein, gates b C being closed.' The aggregates having been mixed as desired, gate C is opened so that the mixed mass is expelled by gravity and by the pressure of the accumulated air, steam or gas within the tank. The valve E is now shifted to cut off the further inflow of the air, steam or gas to the tank and to direct the air, steam or gas into the conduit B, and at or prior to this time the valve 9 is opened for some of the air, steam or gas to flow through'pi'pe G and nozzle g into the delivery section of the conduit, the effect of which is to create a partial vacuumwithin the conduit, whereby the mixed mass is moved through the conduit by the air, steam or gas pressure applied to the rear of the'mass and by the suction created in the delivery section B of said conduit. v

The apparatus of Fig. 2 is similar in all essential particulars to that heretofore described and illustrated in Fig. l, and including the tank A with a gate controlled charging opening, a conduit B with a gate-controlled communication with the tank and having a delivery section B, a'rotary agitator F within the tank, and a valve controlled pressure pipe D connected with the tank. In Fig, 2, however, the 3 position valve is not employed; in lieu thereof, the pressure pipe D is provided with an ordinary stop cock d and air, steamor gas is supplied to the conduit B rearwardly of. the

mixed mass by means of an independent pipe H, the latter being connected to the elbow (l of said conduit for the purpose of discharging the air, steam or gas into the conduit at such a point as to prevent the mixed mass from lodging in the elbow or the conduit, the

inflow of the air, steam or gas being in line substantially with the longituidnal axial line of the conduit, whereby the inflowing air, steam or gas has a tendency to exert a pistonlike action upon the mixed mass for expelling it from the conduit. Pressure pipe is supplied with pressure from a suitable source, being disconnected from pipe D, and this pipe G feeds air, steam or gas to the nozzle g so as to create within conduit B a partial vacuum so as to exert-a suction astion upon the mixed mass, the effect of pressure forwardly and rearwardly of the mixed mass tending to impart movement to said mass for the expeditious transportation within the conduit.

Having thus fully described the invention, what I claim as new, and desire to secure by Letters Patent is 1. In the art of mixing and transporting concrete, the process which consists in feeding a gaseous agent under pressure from below a mass of materials contained within a chamber to initially mix the components of such mass by agitating the same, discharging such initially mixed mass from the chamber into a duct, feeding a gaseous 'agent under pressure to said duct at a point distant from the point of entry of the inithe mass as a whole and effecting a urther mixture of its components by the partial vacuum created Within the duct and by the pressure of the gaseous agent applied rearwardly of such mass.

2. In an apparatus for the class described, a mixing chamber provided with a gatecontrolled mixture-outlet, a ,duct leading from said mixture-outlet of said chamber, means for feeding upwardly within said tank a gaseous motive fluid under pressure whereby the aggregates are pneumatically mixed, the inlet for said feeding means 'to the tank being separate from the mixtureoutlet from said tank, means for feeding to said duct a motive fluid under pressure, said last named feeding means being connected for directing the motive fluid into said duct at a point adjacent the mixture-outlet from the tank, and'controlling means for directing the motivefluid into said tank and into said ductas desired for mixing the concrete and for transporting the same.

3. In an apparatus of the class a mixing tank provided with a gate-controlled mixture-outlet, a duct for receiving a mixed mam adapted to be pneumatically expelled through said mixture-outlet from the tank, means for feeding upwardly within the tank a motive fluid under pressure, the inlet for the upwardly flowing motive fluid being of less cross sectional area than the area of the mixture-outlet, means connected with said duct for feeding thereto a motive fluid under pressure and at a point adjacent the mixture-outlet, and means controllable at will for directing the flow of the motive fluid into said tank and into said duct whereby the concrete is mixed and propelled within the duct subsequently to its ad mimure.

4:. In an apparatus of the class described, a mixing tank provided with a gate-controlled mixture-outlet. a duct for receiving a mixed mass from said tank, means for feeding upwardly within the tank a motive fluid under ressure, the inlet for said motive fluid being of less area than the area of said mixture-outlet, means for feeding to said duct a motive fluid admitted thereto at a point adjacent the mixture-outlet, and a three wa valve for directing the flow of said motive fluid into the tank or into the described, I

duct whereby the concrete is pneumatically said tank for receiving a mixed. mass through said mixture outlet. means for feeding a motive fluid upwardly within said tank, means for feeding to the duct the motive fluid under pressure admitted thereto at apoint adjacent the mixture-outlet from said tank, means for controlling the flow of the motive fluid either to the tank or to the duct, and means for feeding to the duct a motive fluid at a point adjacent the deliv-v cry of the mixed mass whereby the concrete mass is propelled within the duct by partial vacuum and by pneumatic pressure ap plied within the ductrearwardly of the mass therein.

7 In an apparatus of the class described, a mixing tank provided with a gate controlled mixture outlet, a conduit for receiving the mixed mass from said tank, means for feeding a gaseous motive fluid directly to said tank, and means for feeding independently of the feed to the tank a gaseous motive fluid at separated points to the conduit, one of said separated points being adjacent the mixture outlet and the other separated point being adjacent the point of delivery of the mixed mass from saidconduit.

8. In an apparatus of the class described,

a mixing tank, a substantially continuous duct for receiving a mixed mass from said tank and for delivering the same to a distant point means for feeding to the duct a motive fluid under pressure and admitted to said duct adjacent to the mixture-outlet from said tank, and means for feeding to the duct a motive fluid under pressure admitted to said duct at a point rearwardly of the exit for said mixed mass, whereby a partial vacuum is created within the duct and the concrete mass is propelled in part through the energy of pneumatic pressure applied rearwardly thereof and partly through the energy of suction established by the partial vacuum within said duct forwardly of the mass.

ceiving therefrom the mass of materials,

means for feeding a gaseous agent under pressure to said duct at a point remote to the entry to the duct of the initially mixed mass, whereby a partial vacuum is established within that part of the duct leading from the chamber to the place of deposit of the material, and means for feeding a gaseous agent under pressure to the duct adjacent the point of entry of the mixed mass thereinto, whereby the mass of materials is propelled within the duct and its components are further mixed during transit within said duct by'the existence of the partial vacuum and by gaseous pressure applied rearwardly of the mass.

10. In an apparatus for mixing and transporting concrete, a chamber within which is adapted to be contained the components of the mass to be mixed, means for feeding a gaseous agent under pressure to said chamber at a point below such mass to effect agitation of such components, and the initial admixture of the mass, a duct in communication with said chamber, said duct being separate from the feeding means for said gaseous agent, means for controlling communication of the duct with said chamber, means for feeding to the duct a gaseous agent under pressure at a point remote to the entry of the initially mixed mass to said duct, whereby a partial vacuum is established Within said duct and a gaseous agent is supplied to the mass in transit withinthe duct at a point remote to the chamber, and means for feeding to the duct a gaseous agent under' pressure at a point adjacent to the entry of the mass to said duct, whereby the initially mixed mass is propelled within the duct and the components of said mass ai'e further mixed while in transit within the duct by a gaseous agent supplied rearwardly of the mass and asimilar agent supplied to said mass at a point remote to the chamber.

In testimony whereof I have hereunto subscribed my name.

- KARL R. SCHUSTER. 

